Posthole digger



m 9, 1949. b N 2,478,233

POST HOLE DIGGER Filed June 2, 1945 2 Sheets- Sheet 1 IN VEN TOR. CHAEL5 L. BEOW/V.

C. L. BROWN POST HOLE DIGGER Aug. 9, 1949.

Filed June 2, 1945 2 Sheefs-Sheet 2 4 INVENTOR CHARLES L. B/EOh/IV.

WWW

ATTORNEY atented Aug. 9, 1949 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to improvements in post hole diggers of the typeconstructed as attachments for tractors.

The use of mechanical tractors on the farms is very prevalent and manyattachments have been invented to increase the usefulnes of suchtractors.

On farms and ranches it is frequently necessary to build fences and thisrequires the digging of a large number of post holes which has usuallybeen performed by hand tools, such as spades and other hand operateddiggers.

It is the object of this invention to produce a simple and substantialmechanism that can be readily attached to a tractor of any standard makethat is provided with power takeoff and with pumps for delivering oilunder pressure and which can be used for digging post holes where everdesired.

In order to describe this invention so that it may be readilyunderstood, reference will now be had to the accompanying drawings inwhich:

Figure 1 is a side elevation of the invention, portions being brokenaway to better disclose the construction; and

Figure 2 is a longitudinal section taken on line 2-2, Figure 1, aportion being shown in elevation looking through plane 2'2.

In the drawing reference numeral I designates a body or housing having acentral compartment 2 and provided on one side with a trunnion 3.Diametrically opposite and in axial alignment with trunnion 3 is anopening 4 in which a bearing block 5 is threadedly connected. A shaft 6is journaled in the bearing and is provided at its inner end with apinion i. A cooperating hearing block and gasket compressing nut 8 isthreadedly connected with hearing block 5 and serves to compress thepacking material 9. A supporting bracket 80, 8| having two spacedbearings I is rigidly connected with the frame of a tractor which has apower takeoff and a pressure pump, in the manner now common. The bearingto the right in Figure 2 receives the trunnion 3 and the bearing to theleft, the shaft 6. The whole assembly can be rotated about the axis ofshaft 6 in manner which will hereinafter appear. Secured to the outerend of shaft 6 is a pulley ll having a number of V-grooves 52 for thereception of belt that are driven from the power takeoff of the tractor.A drive hub I3 is rotatably mounted on the housing which is providedwith aligned openings It and I through which the hub is inserted andremoved. A bearing block it; is threadedly connectedwith'opening l5 andreceives the cylindrical journal ll of hub l3. A compressor nut l8serves to compress the packing material 19. Positioned in openin It is ahousing plate 20 that is provided with a flange 2| and a central opening22. Threadedly connected with the wall of opening 22 is an annular block23 that serves as a bearing for the reduced cylindrical extension 24 ofhub 13. A compressor nut 25 serves to compress the gasket 26. A look nut21 holds the bearing block 23 in adjusted position. Hub I3 is providedwith an axial opening of square or some other noncircular cros sectionand a babbitt liner 28. A shaft 29, of a cross section corresponding tothe hub opening, is mounted for reciprocation in the liner. Secured tothe hub is a bevel gear 3i) that is operatively related to and connectedwith pinion 1. This gear is held against rotation on the hub by means ofa key 3|. It is now evident that whenever pulley II is rotated, it willimpart a corresponding rotation to the hub and to the shaft that isoperatively connected therewith. the lower end of shaft 29 is providedwith a square section 32 whose lower end terminates in a cylindricalsection 33. A dirt auger 34 is operatively connected with section 32 and33.

A coupling having a cylindrical portion 35 and a radial flange 36 istelescopically connected with the upper reduced cylindrical extension'24 of hub l3 and is held against relative rotation therewith by meansof one or more pins 3?. Cylinder 38 has its lower end positioned in thecylindrical portion 35, and is provided at i lower end with a threadedsection in which ring 39 is secured. Packing gland 40 rests on the uppersurface of ring 39 and supports the special packing ii. Packing ring i2is provided with a cup leather 43 that forms a seal with the shaft 29.Ring 62 rests against an internal shoulder on the cylinder. The cupleather is held in position by means of a packing gland 44. The stufiingbox or packing that has just been described form a liquid tight seal atthe bottom of the operative portion of the cylinder. The upper end ofthe cylinder is closed by means of a cap '35. Secured to the upper endof shaft 29, i a piston comprising a central plate 46 and two rings 41,each of which is provided with a cup leather 3-3. The piston is clampedbetween shoulder 69 and nut 50. It is evident that if oil under pressureis introduced into the cylinder below the piston, the latter will moveupwardly and if oil is introduced between the piston and cap 45, it willexert a force tending to move the piston downwardly.

Positioned above flange 36 is a cylindrical member 5| that is providedat its lower end with a flange 52. This flange is connected with flange36 by means of tap screws 53 and therefore the two parts are heldagainst relative rotation. Positioned above flange 52 is an annular sealcomprising the ring 54 with its cup leather 55 and positioned above thisis another ring which has been designated by reference numeral 56 andwhich is substantially twice as thick as ring 54. R.ing" 56isprovidedwith cup leathers 51 'at the top'an'd at the bottom. "Positionedabove ring 56 is ring 58 that is provided on its upper surface with anannular semi-cylindrical groove 59. Ring 58 has an opening 60, whoseouter :end is threaded for the reception of a pipe 6i. The ringsdesignated by reference numerals '5 1j-"56 and 58 are interconnected andheld against relative rotation by means of one or more pins 62. Rings 58and 56 are held against relativelotation with respect to the housing 63by means of pipes BI and 6A. The latter pipe has its inner end inthreaded connection "with the-walls or opening 65 in ring 55. The innersurfaceof ring 56 has a semi-circular groove fitthatcooperates with asimilar groove in the outer-surface of sleeve "5| so as to provide achannel-or passage extending completely aroundthe outer surface of thesleeve. Opening 87 connects the channel 66 with the'interi-or of thecylinder near the liquid seal-at the bottom-ofthe-cylinder. It is .noWapparent that if oil under pressure is introduced through pipetd, itwill pass into-the cylinder below the piston and-move the latterupwardly. The cylinder andcylindrical member 5| are interconnected 'bymeans 'of one or more pins 68 which to prevent relative rotation.Positioned above ring 58' is a ring 39 that is provided in its undersurface with an annular semicylindrical groove that registers withgroove 59 to form a circular channel. An open-ing'iil con nects thecircular channel 59 with an u'pwa-rdly extending pipe I I. A clampingring 72' isthr'eadedly connected with the uppenendof sleeve --5! andurges ring 59 downwardly into engagement with ring 58. A circularpacking -l3:prevents liquid from escaping outwardly. Clamping ring 12engages a-ring I l of packing material. -Ring 69 is held againstrotation with respect to the cylindrical sleeve 5! by means of a ke1501' some other equivalent means.

It has already been explained that ringst lfit and 58 are held againstrelativerotatien-with respect to the housing 63 by't-he pipes and thepin 6?. Since ring '69 issecure'dto cylindrical sleeve 55 and heldagainst rotation relative thereto and relative to the cylinder,- it isevident that whenever the cylinder is rotated there will be relativerotation between rings--58 andSS. -Pipe H extends upwardly andterminates-in a-down- Wardly projecting pipe fitting'iii that isthreadedly connected with cap-45. The interiorof-pipe BI isthereforealways connected with-the interior of the cylinder at a pointabove the piston.

Pipes 6! and 64 are oonnected with a 4-way valve 11 which, in turn, isconnected with a pres sure pump 13 in the manner indicated inFig-ure 2.Since-pump 7B always-operates, a by-pass T9 is provided so as to permit'the liquid toflow from the outlet to the inlet ports during the timethat the 4-way valve isclosed. Pumps on tractors are always providedwith a valve'corresponding to valve 19.

It has already been pointed out-that the bearings Ii] arejsecured to thetractor insom'e suitable way. Extending upwardly from bearings 4 I0 is arigid bracket that has a laterally extending portion Bl connected withthe tractor. A U-shaped member 82 is connected with bracket 8| bywelding or other means. A worm 83 is rotatably connected to the U-shapedmember and mounted for rotation in bearings provided therefor in thedownwardly extending limbs 84. A crank 85 is connected with the worm andthe worm is operatively connected with the worm 'gea'rtfi. Sincefwormg'ear 8t isn'onrotatably connected with the body l"by mea'-ns of"the key 81, it is evident that whenever crank 85 is operated to turn theworm, the housing I will be :made'to rotate about the axis of trunnion 3in shaft 6 and in this way it can be inclined with respect to thetractor to which bearings ID are connected. This inclination is usefulto make it possible" to'drilfa vertical post hole on land that isinclined. The auger 34 is provided with a helical blade 88 thatterminates in a serrated cutter 89 and-apoint-Bfl.

Let us now-assume that the mechanism above described is secured to atractor and that by means of crank 85., it is'adjusted into Verticalposition and that at the same time the piston is held in its uppermostposition so as to support the point 90 above the ground surface. Bymeans of the power takeoff, pulley II is now rotated, thereby turningthe -hub"l3 and the auger in a direction to make the serrated-edge 89the leading edge of the blade. "The i-way valve is now operated so as toadmit oil to the top of the piston and at the same time allow the oilunderheath the piston to returnto-thepump. The pressure of the oil movestheparts downwardly and forces the auger into theground while it isrotated. The speed at which 'th auger is forced into the ground canberegulated by the operator who controls the openings in valve ll. Whenthe hole has been dug as deep as desired, thee-way valveis reversed,thereby lifting the auger up out of the'grou'nd and ca'rrying with itall of the dirtthat has been cut loose during the down ward movement."The'tra ctor with the attach- 5. ment secured thereto'is then moved toa position where the next hole is to "be 'dug and'the operationrepeated.

Due 'to' the fact that shaft29 caribe raised and lowered to agreater'extent'thanthe depth to which the holes areusuany dug, no othermeans has been provided for raisin andl'owe'ring' the mechanism.

In the above description the'word tractor has been employedinits'broadest sense and it is to be understood that'any suitable machinehaving a power takeoitcanbe used. In fact any vehicle havinga'n enginecapablebf being connected to the digger and operating it 'canbe used. Itis contemplated, of course. that the'machine shall be used'withanorainarrerm tractor of any kindfor in connection with a truck.

The machine can dig holes of varioussizes from eight inchesor smaller,to'two feet. The size of'hole depends'on the size'of the ground augerused, and of any depth up to eight feet which is the capacity of thepresent machine. The depth to which it will operate depends ontheile'ngthbf the cylinder andsha'ft'29. Having described the invention,what is claimed as new is:

In a post "hole digger attachment for use with tractors having 'a powertake-off, a pressure pump; a ho us'ing,'verjtically spaced axiallyaligned bearings "carridby' the housing, a' hub' mounted i'n'thebearings, nieans'ror turning the hub with lower end of the cylinder, apiston carried by 10 the upper end of the auger shaft additional hear--ing means for said cylinder connected to the housing, fluid passages insaid last mentioned bearing means, conduits connecting said pump to saidhousing, said conduit being respectively aligned with said passages,means providing a fluid conduit from one of said passages to the upperend of said cylinder, means providing a fluid conduit from the other ofsaid passages to the lower end of said cylinder, and valve means 20 1,7,172

interposed in the conduits which connect the pump to the housing toselectively control the flow of fluid to the cylinder to force liquidunder pressure to one side of the piston and remove it from the otherside thereof or vice versa while the cylinder is rotating in thehousing.

CHARLES L. BROWN.

REFERENCES CITED The following referenlces are of record in the flle ofthis patent:

UNITED STATES PATENTS Number Name Date 557,686 Meissner Apr. 7, 18961,612,226 Sheldon Dec. 28, 1926 1,627,539 Halleck May 3, 1927 1,692,431Anderson Nov. 20, 1928 Smith et al.. NOV. 8, 1932

